The present invention relates to an appearance inspecting device for inspecting appearances of solid formulations each having a shape being rotation-symmetric around a specific axis, and particularly to an appearance inspecting device suitable for inspecting appearances of capsules in each of which a hard capsule piece having a cap and a body is filled with a medicine or appearances of empty capsules in each of which a cap and a body are only temporarily connected to each other before being filled with a medicine. In more particular, the present invention relates to an appearance inspecting device capable of inspecting solid formulations to be inspected at high accuracies by photographing the solid formulations using an image pickup device while rotating the solid formulations in accurately positioned states.
Conventionally, as an appearance inspecting device for automatically inspecting appearances of solid formulations such as capsules or elliptical ball-like tablets, various types have been proposed, and in recent years, visual inspection for solid formulations by a worker is being perfectly shifted to automatic inspection for solid formulations using such an automatic inspecting device. The appearance inspecting device of this automatic type is known, for example, from Japanese Patent Laid-open No. Hei 7-35693.
The appearance inspecting device disclosed in Japanese Patent Laid-open No. Hei 7-35693, having a configuration shown in FIGS. 6 to 8, is mainly used to inspect appearances of capsules in each of which a hard capsule piece having a cap and a body is filled with a medicine.
As shown in FIG. 6, this appearance inspecting device includes a supply hopper 2, a supply drum 3, a first direction restricting drum 4 and a second direction restricting drum 5, an inspecting drum 6, an image pickup device 7, a quality determining section 8, and a classifying/recovering section (not shown). The supply hopper 2 is adapted to contain a predetermined number of capsules and sequentially supply the capsules. The supply drum 3 is adapted to align the capsules supplied from the supply hopper 2 in upright states with axial lines of the capsules directed up and down (hereinafter, referred to simply as "upright states") and to supply the capsules thus aligned to the first and second direction restricting portions 4 and 5. The first and second direction restricting sections 4 and 5 are adapted to restrict directions of the capsules supplied from the supply drum 3 in laterally-turned states with the axial lines of the capsules directed in the horizontal direction (hereinafter, referred to simply as "laterally-turned states") and also with the cap sides thereof directed in a specific direction. The inspecting drum 6 is adapted to carry the capsules thus direction-restricted while holding the capsules on an outer peripheral portion thereof and to rotate the capsules in the course of carrying the capsules. The image pickup device 7 is adapted to photograph the capsules rotated while being held on the outer peripheral portion of the inspecting drum 6 and to pick up images of the capsules. The quality determining section 8 is adapted to process the images thus picked up by the image pickup device 7 and to determine whether the capsules are defective or nondefective. The classifying/recovering section is adapted to classify the capsules supplied from the inspecting drum 6 into nondefective capsules and defective capsules on the basis of the results determined by the quality determining section 8. In addition, in this specification, the term "up and down" for the capsules held on the outer peripheral portion of each drum means that the "up" side is equivalent to the outer peripheral side along the radial direction of the drum and the "down" side is equivalent to the center side along the radial direction of the drum; and the term "horizontal direction" for the capsules held on the outer peripheral portion of each drum means the direction perpendicular to the radial direction of the drum. That is, the "up and down" and the "horizontal direction" in this specification are not necessarily identical to the [up and down] and the [horizontal direction] based on the gravity direction.
The supply drum 3 is rotated around a horizontal axis A1 at a specific rotational speed, and it has on an outer peripheral surface thereof a plurality of supply pockets 31 for containing capsules at upright states. To prevent falling of the capsules contained in the supply pockets 31 therefrom, a falling preventive plate 32 is disposed to cover a lower side one-fourth portion of the outer periphery of the supply drum 3.
The supply hopper 2 is disposed over the supply drum 3. A lower end surface of the supply hopper 2 is partially in proximity to the outer peripheral surface of the supply drum 3, and part of the lower end surface of the supply hopper 2 is opened to the outer peripheral surface of the supply drum 3. A plurality of guide projection ribs 21, spaced at specific intervals, vertically project from a bottom portion of the supply drum 2. Between these guide projection ribs 21 are formed guide grooves 22 for aligning capsules. The guide grooves 22 are disposed at positions corresponding to those of the supply pockets 31 of the supply drum 3. The width of the guide groove 22 is slightly wider than a diameter of each capsule and is narrower than a length of a capsule. Accordingly, capsules pass through the guide grooves 22 with axial lines thereof directed in the length direction of the guide grooves 22, being inserted in the supply pockets 31 of the supply drum 3 with either of axial ends of the capsules being at the head, and are contained in the supply pockets 31 in the upright states.
The supply hopper 2 is usually vibrated by a vibration generator (not shown) for allowing the capsules in the supply hopper 2 to be smoothly contained in the supply pockets 31 of the supply drum 3 through the guide grooves 22. The capsules, which are not contained in the supply pockets 31 and are moved on an outer peripheral surface of the supply drum 3, are ejected from the surface of the supply drum 3 by a brush 23 disposed on the supply drum 3 along an edge portion of the supply hopper 2 and are returned again in the supply hopper 2.
The first direction restricting drum 4 is disposed under the supply drum 3 in such a state that an outer peripheral surface thereof is in proximity to the outer peripheral surface of the supply drum 3. The first direction restricting drum 4 is rotated around a horizontal axis A2 at a specific speed in the rotational direction reversed to that of the supply drum 3. A plurality of first direction restricting pockets 41 are formed in the outer peripheral surface of the first direction restricting drum 4 in such a state as to be aligned at positions corresponding to those of the supply pockets 31 of the supply drum 3. As shown in FIG. 8, the first direction restricting pockets 41 are composed of oblong-like upper portions 41a and vertical cylinder-like lower portions 41b formed on bottom surfaces at one-end portions of the upper portions 41a. The oblong-like upper portion 41a is allowed to perfectly contain a capsule in the laterally-turned state, and the vertical cylinder-like lower portion 41b is allowed to receive only the body of a capsule, that is, not to receive the cap thereof. With this configuration, the first direction restricting pocket 41 can perfectly contain a capsule C1 in the laterally-turned state and a capsule C2 in an upright state with the axial line thereof directed up and down and with the cap directed upward (hereinafter, referred to as "an upright state with the cap directed upward"); however, the first direction restricting pocket 41 cannot perfectly contain a capsule C3 in an upright state with the axial line thereof up and down and with the body directed upward (hereinafter, referred to as "an upright state with the body directed upward"), that is, it receives the capsule C3 in a state in which the body portion projects from the outer peripheral portion of the first direction restricting drum 4.
As shown in FIG. 6, a guide plate 42 is disposed in the vicinity of the outer peripheral surface of the first direction restricting drum 4 in such a manner as to partially surround the outer peripheral surface of the first direction restricting drum 4. A plurality of guide grooves 43 functioning as first direction restricting guides, in each of which one end is open and the other end is closed, are disposed on the guide plate 42 at positions corresponding to those of the first direction restricting pockets 41 of the first direction restricting drum 4. One inner edge portion of the guide groove 43 constitutes a pushing portion 43a tilted at a specific angle from the rotational direction of the first direction restricting drum 4. The pushing portion 43a is adapted to push the end portion of the body side of the capsule C3 (see FIG. 8) projecting from the outer peripheral surface of the first direction restricting drum 4, to thus laterally turn it in the first direction restricting pocket 41.
The second direction restricting drum 5 is disposed under the first direction restricting drum 4 in such a state that an outer peripheral surface thereof is in proximity to the outer peripheral surface of the first direction restricting drum 4. The second direction restricting drum 5 is rotated around a horizontal axis A3 at a specific speed in the rotational direction reversed to that of the first direction restricting drum 4. A plurality of second direction restricting pockets 51 are formed in the outer peripheral surface of the second direction restricting drum 5 in such a state as to be aligned at positions corresponding to those of the first direction restricting pockets 41 of the first direction restricting drum 4. As shown in FIG. 8, the second direction restricting pocket 51 is an oblong-like pocket which can perfectly contain the capsule C1 in the laterally-turned state and which receives the capsule C3 in the upright state in a state in which the end portion of the body side thereof projects from the outer peripheral surface of the second direction restricting drum 5. In this pocket 51, a bottom wall thereof is tilted downward to one end side, so that the capsule is contained in the pocket 51 in a state being shifted to the one end side.
As shown in FIG. 6, a guide plate 52 similar to the above guide plate 42 disposed along the outer periphery of the first direction restricting drum 4 is also disposed in the vicinity of the outer peripheral surface of the second direction restricting drum 5. While not shown, a plurality of guide grooves provided in the guide plate 52 constitute second direction restricting guides. The guide groove is adapted to laterally push the end portion of the body side of the capsule C3 projecting from the outer peripheral surface of the second direction restricting drum 5, to thus laterally turn the capsule C3 in the second direction restricting pocket 51.
The above drums 3, 4 and 5 are rotated, as shown typically in FIG. 6, by a motor M1 and a timing belt B in the direction shown by an arrow in FIG. 6 at such a timing as to allow the pockets 31, 41, and 51 to be aligned to each other.
The supply hopper 2, supply drum 3, first direction restricting drum 4, and second direction restricting drum 5 constitute a supply section for supplying capsules, as objects to be inspected, to the inspecting drum 6. In this case, capsules supplied from the supply hopper 2 at random are aligned in upright states by the supply drum 3, being all direction-restricted in laterally-turned states with cap sides thereof directed in a specific direction by the first and second direction restricting drums 4 and 5, and are supplied to the inspecting drum 6.
The inspecting drum 6 is disposed under the second direction restricting drum 5 in such a state that an outer peripheral surface is in proximity to the outer peripheral surface of the second direction restricting drum 5. The inspecting drum 6 is intermittently rotated around a horizontal axis A4 at a specific speed in the rotational direction reversed to that of the second direction restricting drum 5. The inspecting drum 6 includes a pair of disk-like flanges 61 oppositely spaced at a specific gap, and a plurality of first inspecting rollers 62a and a plurality of second inspecting rollers 62b which are rotatably provided between the flanges 61.
As shown in FIG. 7, both the flanges 61 are fixed on both end portions of an intermittently rotatable body 65 rotatably supported around a non-rotatable shaft 64 fixed on a frame 63. The intermittently rotatable body 65 is fixedly connected to a flange 66a formed on a base end side of an intermittently rotatable shaft 66 rotatably supported around a central portion of the non-rotatable shaft 64, and is rotatable integrally with the intermittently rotatable shaft 66. The intermittently rotatable shaft 66 is connected to an intermittently driving device D, to be thus intermittently rotated by the device D. Thus, the intermittently rotatable body 65 and the flanges 61 are rotated integrally with the intermittently rotatable shaft 66.
The first inspecting rollers 62a and the second inspecting rollers 62b are alternately disposed along the peripheral surface of the inspecting drum 6 in a state in which outer peripheral surfaces of both the rollers 62a and 62b are in proximity to each other. The rollers 62a and 62b are rotatably mounted between peripheral edge portions of the flanges 61. One-end portions of shafts 621a and 621b of the first and second inspecting rollers 62a and 62b pass through one of the flanges 61 and project outward therefrom, and planetary gears 622 are fixed to the projecting end portions of the shafts 621a and 621b. The planetary gears 622 are meshed with a sun gear 623 rotatably mounted on a base end portion of the intermittently rotatable shaft 66. A pulley 624 fixed on the sun gear 623 is connected to another pulley 625 mounted on a rotational shaft of a motor M2 through a timing belt 626. With this configuration, the sun gear 623 is rotated by the motor M2 through the timing belt 626 and the planetary gears 622 are rotated around the sun gear 623, so that the first and second inspecting rollers 62a and 62b integrated with the planetary gears 622 are rotated at a specific speed independently from the intermittent rotation of the flanges 61. To be more specific, the first and second inspecting rollers 62a and 62b are rotated on their axes while being revolved together with the flanges 61. In addition, the rotational direction of the first inspecting roller 62a is the same as that of the second inspecting roller 62b.
Capsules C4 supplied from the second direction restricting drum 5 in the state being direction-restricted are placed and held between the first and second inspecting rollers 62a and 62b, and are revolved around the non-rotatable shaft 64 while being rotated on their axes by the revolution and rotation of the first and second inspecting rollers 62a and 62b.
In this case, a plurality of flange portions 62c are formed on outer peripheral surfaces of the first inspecting rollers 62a in such a manner as to be spaced at equal intervals. As shown in FIG. 9, the capsules C4 are rotated on their axes and revolved in a state being held between the flanges portions 62c. Further, as shown in FIG. 7, nozzles 651 are formed in the intermittently rotatable body 65 at positions corresponding to the portions for holding the capsules. Besides, a suction cavity portion 641 communicated to a suction device (not shown) such as a vacuum pump is formed in the non-rotatable shaft 64 in such a manner as to extend nearly around a semi-periphery of the non-rotatable shaft 64, and compressed air flow passages 642 communicated to a compressed air supply device (not shown) such as a compressor are formed at positions corresponding to a defective capsule recovery can 71 (see FIG. 6) and a nondefective capsule recovery chute 72 (see FIG. 6). The nozzles 651 are sucked in vacuum through the suction cavity portion 641 to certainly hold the capsules C4 by the suction force, and compressed air is jetted from the nozzles 651 through the compressed air flow passages 642 to blow the capsules C4 into either the defective capsule recovery can 71 or nondefective capsule recovery chute 72 by the compressed air.
The appearance inspection for capsules using such a related art appearance inspecting device is performed as follows: First, a-predetermined number of capsules charged in the supply hopper 2 are sequentially supplied into the supply drum 3 in the upright states by the above-described action, being contained in the upright states in the supply pockets 31 formed in the outer peripheral surface of the supply drum 3, and carried downward by the rotational motion of the supply drum 3.
As shown in FIG. 8, when reaching the lowermost portion of the supply drum 3, the capsules are transferred from the supply drum 3 to the first direction restricting pockets 41 of the first direction restricting drum 4. At this time, the capsules C2 transferred in the upright states with the caps thereof directed upward are nearly perfectly contained in the pockets 41 in the states in which the body portions are inserted in the lower portions 41b of the first direction restricting pockets 41. On the other hand, the capsules C3 transferred in the upright states with the caps directed downward are received in the pockets 41 in the states in which the body portions project from the outer peripheral surface of the first direction restricting drum 4 because the cap portions are not inserted in the lower portions 41b of the first direction restricting pockets 41.
These capsules C2 and C3 are carried downward in these states by rotation of the first direction restricting drum 4. At this time, the capsules C2 nearly perfectly contained in the first direction restricting pockets 41 are carried to the lowermost portion of the drum 4 as left in these postures. Besides, with respect to the capsules C3 with the body portions projecting from the outer peripheral surface of the drum 4, the body portions are inserted in the guide grooves 43 of the guide plate 42 (see FIG. 6) and are laterally pushed by the pushing portions 43a of the guide grooves 43 (see FIG. 6). As a result, the capsules C3 are laterally turned in the first direction restricting pockets 41 and are carried to the lowermost portion of the drum 4 as the capsules C1 in the laterally-turned states with the caps directed in one direction (right side in FIG. 8).
Next, as shown in FIG. 8, when reaching the lowermost portion of the first direction restricting drum 4, these capsules C2 and C1 are transferred from the drum 4 to the second direction restricting pockets 51 of the second direction restricting drum 5. At this time, the capsules C1 in the laterally-turned states are nearly perfectly contained in the second direction restricting pockets 51 as left in the laterally-turned states. On the other hand, the capsules C2 in the upright states with the caps directed upward are transferred in the second direction restricting pockets 51 with the cap sides being at the head and thereby they are turned over in the vertical direction. In other words, the capsules C2 are transferred in the second direction restricting pockets 51 as the capsules C3 in the upright states with the bodies directed upward. With respect to the capsules C3, the body portions project from the outer peripheral surface of the second direction restricting drum 5.
The capsules C1 and C3 in these states are carried downward by rotation of the second direction restricting drum 5. At this time, the capsules C1 in the laterally-turned states, which are nearly perfectly contained in the second direction restricting pockets 51, are carried to the lowermost portion of the drum 5 as left in the postures. Beside, the capsules C3 with the body portions projecting from the outer peripheral surface of the drum 5 are laterally turned in the second direction restricting pockets 51 in the same manner as described above by the action of the guide grooves (not shown) of the guide plate 52 (see FIG. 6) to be converted into the capsules C4 in the laterally-turned states with the caps directed in one direction (right side, in the figure), and are carried to the lowermost portion of the drum 5. Thus, both the capsules C1 and C3 are converted into the capsules C4 in the laterally-turned states with the caps directed in one direction (right side, in the figure), and are transferred onto the first and second inspecting rollers 62a and 62b of the inspecting drum 6.
In addition, as shown in FIG. 8, upon transfer of the capsules between the drums 3, 4, 5 and 6, compressed air is supplied to respective pockets on the delivery side to push out the capsules while portions of respective pockets and rollers 62a on the receiving side are sucked in vacuum to attain smooth transfer of the capsules.
The capsules C4 supplied to the inspecting drum 6 in the state being direction-restricted are, as described above, placed and held between the first and second inspecting rollers 62a and 62b, and are carried downward by intermittent rotation of the inspecting drum 6 while being rotated by rotation of the first and second inspecting rollers 62a and 62b. In this case, as shown in FIG. 9, the capsules C4 are carried while being rotated in the state being held between the flange portions 62c of the first inspecting rollers 62a, and at this time, the capsules C4 are sucked and held between both the inspecting rollers 62a and 62b by the above-described sucking mechanism.
The capsules C4 thus held and carried by the inspecting drum 6 in the states being direction-restricted are photographed by the image pickup device 7 (see FIG. 6) during a period for which the rotation of the inspecting drum 6 is stopped at a specific position in the course of carrying of the capsules C4. At this time, each capsule C4 is rotated at least one turn or more at a specific speed by rotation of the first and second inspecting rollers 62a and 62b, so that the entire peripheral surface of the capsule C4 is photographed by the image pickup device 7. After photographing, the capsules C4 are carried to the lowermost portion of the inspecting drum 6 by intermittent rotation of the inspecting drum 6 while being held between the first and second inspecting rollers 62a and 62b.
The image of each capsule C4 picked up by the image pickup device 7 is processed by the above quality determining section 8 (see FIG. 6). The quality determining section 8 determines a quality of each capsule C4 by detecting whether the appearance of the capsule C4 is defective or nondefective. On the basis of the determined result, each capsule C4 is blown down either in the defective capsule recovery can 71 or in the nondefective capsule recovery chute 72 by the above-described compressed air jetting means. The capsules are thus classified into defective and nondefective capsules and are recovered.
In this case, a position at which the capsule being defective in appearance is to be blown down in the defective capsule recovery can 71 is before the nondefective capsule recovery chute 72. At such a position, compressed air is jetted on the basis of an instruction supplied from the quality determining section 8. That is, at the position before the nondefective capsule recovery chute 72, only the capsule judged to be defective by the above determined result is blown down by compressed air. On the other hand, at a position where a nondefective capsule is to be blown down into the nondefective capsule recovery chute 72, compressed air is usually jetted to all of the capsule holding portions. All of the capsules C4 reaching such a position are thus blown down in the nondefective capsule recovery chute 72. In summary, the capsules defective in appearance are ejected from the inspecting drum 6 at the position before the nondefective capsule recovery chute 72 and recovered into the defective capsule recovery can 72, and only the capsules not defective in appearance are discharged from the nondefective capsule recovery chute 72 to the outside of the inspecting device.
In this way, according to the related art appearance inspecting device, appearances of capsules can be perfectly automatically inspected by the steps of aligning capsules charged at random with caps thereof being directed in a specific direction, photographing the capsules thus direction-restricted by the image pickup device while rotating the capsules, determining whether the appearances of the capsules are defective or nondefective on the basis of the images thus obtained, and classifying the capsules into nondefective and defective capsules and recovering the nondefective and defective capsules.
The related art appearance inspecting device, however, has been insufficient in terms of inspecting accuracy, and it has not been practically used from the viewpoint of inspecting performances.
To be more specific, in the above-described related art appearance inspecting device, as shown in FIG. 9, the capsule C4 is positioned in a state being held between the flange portions 62c of the first inspecting roller 62a, and in such a state, an image of the capsule C4 is photographed by the image pickup device 7. In this case, since the width "W" between the flange portions 62c is set to be slightly wider than the length "L" of the capsule C4 in order to certainly smoothly perform transfer of the capsule C4 from the second direction restricting drum 5, the capsule C4 held between the flanges 62c are rotated while being finely moved or vibrated in the axial direction, as a result of which, the image of the capsule cannot be picked up in a state in which the capsule is accurately positioned.
The image of the capsule thus obtained, therefore, contains not a little disturbance due to deviation of the capsule upon rotation thereof. Consequently, if qualities of capsules are strictly determined on the basis of image processing, most of capsules including a large number of nondefective capsules may be possibly determined to be defective. For this reason, a criterion for determining whether appearances of capsules are defective or nondefective must be set in consideration of the fact that deviation of capsules occurs to some extent. This makes it impossible to attain a high inspection accuracy. In particular, a stepped portion is necessarily formed on the surface of a capsule at a boundary between a cap and a body, and a failure such as a fine split-like damage or crack is liable to be produced in the vicinity of the stepped portion upon connection of the cap to the body. In general, to detect such a failure while identifying it from the stepped portion, there has been adopted a method in which a change in image data due to the stepped portion is previously stored and an abnormality different from the change thus stored is recognized as defective in appearance. In the case where the stepped portion is irregularly moved by deviation of the capsule, however, it is substantially impossible to previously accurately estimate and store a change in image data due to the stepped portion, and since a position on an image at which a change in data due to the stepped portion occurs cannot be specified, it is very difficult to detect a failure such as a damage or crack at a boundary between a cap and a body while identifying it from the stepped portion. It should be noted that in the case where a band seal is attached to a boundary between a cap and a body, the same problem also occurs.
Further, in capsules, the connection lengths between caps and bodies are not necessarily specified depending on manufacturing factors, and accordingly, the lengths L of the capsules are varied somewhat, that is, not specified. For this reason, the width "W" between the above flanges 62c (see FIG. 9) must be set wide with an appreciable allowance. And, in the case where a capsule having an entire length L being so relatively short as not to be defective is held between the flanges 62c which are set such that the width "W" is relatively wider with the appreciable allowance as described above, deviation of the capsule during rotation thereof becomes significant, and in such a case, it is impossible to normally perform appearance inspection for the capsule.
Further, although a capsule with its length L over a specific allowance range must be ejected as a defective capsule because the filling amount of a medicine is varied or connection between a cap and a body is insufficient, the related art appearance inspecting device fails to actually inspect the capsule being defective in length because the capsule is rotated while being moved or vibrated in the axial length, that is, in the length direction as described above and the capsule is subjected to appearance inspection in the condition that such a deviation is allowed.